Ring cone-shaped diaphragm device



Au 22s, 1928.

1,682,611 E. H. FOLEY ET AL RING CONE SHAPED DIAPHRAGM DEVICE Filed 001;. 8, 1925 Patented Aug. 28, 1928.

UNITED STATES PATENT oF iC-E.

EARL FOLEY AND PAUL J. G-UNN, OF TACOMA, WASHINGTON, ASSIGNORQTO INTER- NATIONAL ACOUSTIGRAIPH COMPANY, OF TACOMA; WASHINGTON.-

RING CONE-SHAPED DIAPHRAGM DEVICE.

Application fi led October 8, 1925; Serial No. 61,250.

Our present invention relates, in its broad aspect, to improvements in diaphragm devices for use with electro-magnetic and other sound reproducing instruments of the loud speaker type, and more particularly it is our purpose to provide a diaphragm of such form and construction that the maximum efficiency is attained. To accomplish these and other equally important ends We have provideda conical diaphragm, the peculiar configuration of which causes a much greater and more uniform displacement of air under vibratory impulses than has heretofore been attained by planetary (or flat) or otherwise shaped or contoured diaphragms. Not only have we by these means improved upon other diaphragms with regard to the efficiency of their vibrations per se, but we have gone a step further in that so-called synthetic vibrations and conflicting harmonics are eliminated by the formation about the conical diaphragm of an annular ring, the material of which we have stretched to a period of vibration above that of audiofrequency. The peculiar formation of our diaphragm also lends toward the attainment of greater rigidity'than has been found feasible in circular planetary diaphragms, although the inertia is not so great that distortion is induced in the reproduction of sound waves, and furthermore our diaphragm is symmetrical in configuration thereby facilitating its manufacture and improving upon those peculiarly contoured planetary diaphragms which have recently been designed to produce a more uniformly vibrating area.

The structural elements and other means employed to accomplish the above and other equally important objects and advantages will be hereinafter more fully described in detail and specifically pointed out in the claims appended hereunto and forming a part of this specification, but the scope of our limits defined in the claims.

In the accompanying drawin s wherein is illustrated the preferred embodiment of our invention I Figure 1 is a side view of our diaphragm,

Figure 2 is a sectional side view of our diaphragm showing conventionally a means of electro-magnetically vibrating the same, and

invention may only be determined by the Figure 3 is a top plan view of our diaphragm. I

In the drawing wherein like characters of reference designate like or similar parts throughout the several views The numeral 1 designates our conical diaphragm which is formed with a peripheral flange 2 and an intermediate rib 3. The rib 3 and flange 2 are, of course, integral with the diaphragm and annular in configuration,

and the material of the rib 3 is stretched in the making to have a period of vibration above that of audio-frequency, thereby eliminating synthetic audible vibrations and harmonics.

'By the term stretched we mean that the structure of the rib 3 has been placed under high tension in itsformation, and that such tension is not lost or appreciably relaxed in the finished article. The result upon the period of vibration of the rib is similar to that producedvby the stretching of a piano wire, i. e., the more the piano wire is stretched or placed under tension the higher becomes its period of vibration. Accordingly, our use of the term stretched should not be con- 5 fused with such terms as reduced in thickness or the like which refer primarily to the physical properties of an object in relation to its size, thlckness, or weight.-

A practical form of electro-magnetic apparatus provided to induce vibrations in our diaphragm includes a rod 4 carried or engaged by the armature 5 of electro-magnet 6, and this rod 4 engages the diaphragm at its apex 7. Embracing the end ofthe rod is a spring 8 which abuts a supporting element 9 carried by the diaphragm casing (not and arrangement of elements as constitute the preferred embodiments of our invention, it is nevertheless desired to emphasize the fact that interpretation of the invention should only be conclusive when made in the li ht of. the subjoined claims.

We claim 1. In-a diaphragm device, a primary vibrating area having a period of vibration within the scale of audio-frequency, a laterally extending flange about the periphery. of said area for attaching the diaphragm in a frame, and a rib integral with the flange and the primary vibrating area, and-between the two, the material of which is under tension at all times to have a period of vibration above the scale of audio-frequency vibrations.

2. In a diaphragm device, a conical pri mary vibrating area having a period of vibration within the scale of audio-frequency, a laterally extending flange about the periphery of said area for attaching the diaphragm in a frame, and a U-shaped rib integral with the flange and the primary vibrating area, and between the two and opening toward the base of the cone, the material of which is under tension at all times to have a period of vibration above the scale of audiofrequency vibrations.

In testimony hereof we aflix our signatures hereunto.

EARL H. FOLEY. PAUL J. GU NN. 

